The 90s are back. And so are the backpacks and bum bags made popular by the grunge movement. Bum bags are slung low around your hips, and backpacks -- well, you know where they're worn. Designers like Marc Jacobs and Louis Vuitton have updated these packs with embossed leather, tassels and even fur tails. But don't worry; if you can't afford designer prices, retailers like American Apparel are using nylon and denim to construct hip backpacks and bum bags that sell for affordable prices.